diff --git a/lib/http.js b/lib/http.js
index a66ed0d..2ae26f2 100644
--- a/lib/http.js
+++ b/lib/http.js
@@ -352,7 +352,7 @@ var HTTPObject = function(engine) {
                     var state = this.states[this.states.length - 1];
                     var cmd = ["bin\\curl", "-X", this.method];
 
-                    if (this.headers.length > 0) {
+                    if (Object.keys(this.headers).length > 0) {
                         for (var key in this.headers) {
                             var value = this.headers[key];
                             if (value != null) {